xfail tests that are currently failing on windows, reported in #7999
libstd: Implement {peer, socket}_name for new rt tcp & udp.
libstd: Fix errors when rtdebug! is not a noop.
libstd: Handle IPv4-Mapped/Compatible IPv6 addresses.
debuginfo: Implemented support for destructured locals.

Conflicts:
	src/librustc/middle/trans/debuginfo.rs
	src/test/debug-info/destructured-local.rs
debuginfo: Support for function arguments. (WIP)
debuginfo: Support for destructured function arguments.
debuginfo: Minor cleanup now possible with new snapshot.
libstd: Get rid of duplication in {peer, socket}_name and remove extra *.
debuginfo: Fixed a few things for PR.
Added default impls for container methods

A couple of implementations of Container::is_empty weren't exactly
self.len() == 0 so I left them alone (e.g. Treemap).
libstd: Add ToStr impl for IpAddr.
libstd: Implement some missing tcp methods.
libstd: Implement some missing udp methods.
libstd: Tests for {peer, socket}_name.
syntax: fix span for obsolete extern visibility error
Deny all warnings by default in doc tests

Allow some common ones that are good for examples, however.
librustc: Respect no_mangle attribute on statics.
librustc: Unify name mangling for functions and statics.
auto merge of #8001 : crnobog/rust/xfail-win32-7999, r=cmr